From 3475ea5f0709e8672ea7ad317ac92a55dcc4b37a Mon Sep 17 00:00:00 2001
From: Ryan Lamb <4955475+kinyoklion@users.noreply.github.com>
Date: Thu, 7 May 2026 15:14:51 -0700
Subject: [PATCH] feat: add isClosed observer to TestSseClient

Lets test code assert that the SUT correctly tears the SSE
connection down. Test-only addition; the production SSEClient
implementations do not expose this state, and the TestSseClient
class is already documented as test-only with no semver guarantee.
---
 packages/event_source_client/lib/src/test_sse_client.dart | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/event_source_client/lib/src/test_sse_client.dart b/packages/event_source_client/lib/src/test_sse_client.dart
index d65df43..c8f497e 100644
--- a/packages/event_source_client/lib/src/test_sse_client.dart
+++ b/packages/event_source_client/lib/src/test_sse_client.dart
@@ -37,6 +37,12 @@ final class TestSseClient implements SSEClient {
   bool hasCapability(SSECapability capability) =>
       _capabilities.contains(capability);
 
+  /// Whether [close] has been called on this client. Test-only --
+  /// production [SSEClient] implementations do not expose this state,
+  /// and tests asserting against it are inherently white-box. Use to
+  /// verify that code under test correctly tears the connection down.
+  bool get isClosed => _messageEventsController.isClosed;
+
   /// Emit an event on the stream.
   /// Has no effect if the client has been closed.
   ///